Food is chewed by teeth such that upper and lower teeth are aligned through movement of jaw joints.
If teeth are damaged, misalignment may be caused, resulting in dental dysfunction. In this case, in order to cure the damaged teeth, prosthetic appliance may be used. In fabricating the prosthetic appliance, an articulator is used to check a teeth alignment state.
A dental model articulator is a device to assist to process prosthetic appliance to allow the prosthetic appliance to be compatible with existing teeth by mounting dental models and simulating jaw joint movement.
There are numerous types of articulators ranging from very simple openable type devices to highly sophisticated and mechanically complex devices. In general, based on the adjustability factor, articulators fall into the following categories: nonadjustable articulators, semiadjustable articulators, and fully adjustable articulators.
The nonadjustable articulator includes a hinge type articulator and an average movement articulator. The hinge type articulator is a simplest type articulator that is not structurally adjustable but is capable of moving only up and down in open and closed positions or lateral movement in a limited range.
Since the average movement articulator having a condylar guidance angle of 30° on the average is fixed, it is not possible to adjust individuals having different condylar guidance angles. When tooth models are attached to the average movement articulator, only the occlusal record at the centric position between upper and lower jaws is necessary, there is no way of adjusting a condylar path. However, since the average movement articulator is capable of moving maxillary member, it has the advantage of lateral movement.
The semiadjustable articulator is capable of adjusting condylar paths and is adjustable by a centric occlusal record, anterior occlusal record and a lateral occlusal record, thereby producing an improved denture or restorative material, compared to a case where the nonadjustable articulator.
The fully adjustable articulator is most sophisticated but is mechanically complex, requiring much more complicated preparation and manipulation works than the semiadjustable articulator. Thus, it is quite difficult to commercialize the fully adjustable articulator.
Meanwhile, in a dental technologist's office or laboratory, the articulators are suitably utilized based on their characteristics. The nonadjustable articulator, specifically, the hinge type articulator is hardly used. The average movement articulator is typically used in temporary dentures, mechanically simple crowns or bridges, and so on. The semiadjustable articulator having a wide variety of dental applications are suitably used with fabrication of complete dentures or partial dentures.
Among the articulators, an average movement articulator is disclosed in Korean Utility Model Registration No. 0220295. The disclosed articulator is configured such that a maxillary dental model cast is fixedly combined with an upper model fixing unit using plaster, etc. and a mandibular dental model cast is then combined with a lower model fixing unit using plaster, etc. However, since the conventional articulator uses plaster, quite a long time is required to harden the plaster. In addition, once the casts are fixedly combined, it is not easy to separate the casts.
In particular, it is necessary to accurately align and fix occlusal positions of the maxillary dental model cast and mandibular dental model cast. However, in a case where the occlusal positions are misaligned, the misalignment cannot be corrected.